DCC Braking

[sjrixon]

Hi All,

 

I'm dabbling with DCC, one loco, one RocoMultiMaus controller, early days

 

Having set cv3 and 4, I'm amazed at how smoothly the loco accelerates and decelerates. This is something I hadn't really appreciated with the change from DC to DCC, it makes everything feel a lot more realistic. 

 

Do any decoders or controllers have any enhancements to the braking? All was going well until I went a little fast and ran the loco hard into the buffers as my brake setting was a little too long/high. It is an if you also need 'brake' function to add a little more force than waiting for the loco to just slow down.

 

Scott

[Reorte]

I'm by far from a DCC expert but I think most controllers have an emergency stop button for those situations. As far as realstic operation goes even an emergency brake application doesn't stop a train very rapidly (by e.g. car standards).

 

I'll leave it to the vastly more knowledgeable to tell you whether or not you can select different braking rates whilst running.

[Suzie]

It is a feature of the decoder, some better decoders give you a function to switch off the inertia, and the function number varies.

[pauliebanger]

It is a feature of the decoder, some better decoders give you a function to switch off the inertia, and the function number varies.

 

Hi All,

 

I'm dabbling with DCC, one loco, one RocoMultiMaus controller, early days

 

Having set cv3 and 4, I'm amazed at how smoothly the loco accelerates and decelerates. This is something I hadn't really appreciated with the change from DC to DCC, it makes everything feel a lot more realistic. 

 

Do any decoders or controllers have any enhancements to the braking? All was going well until I went a little fast and ran the loco hard into the buffers as my brake setting was a little too long/high. It is an if you also need 'brake' function to add a little more force than waiting for the loco to just slow down.

 

Scott

 

Scott,

 

You may be new to DCC but you have hit the nail on the head by identifying this shortcomng of most DCC decoders.

 

ZTC controllers have a separate Brake Function. This works independently of the decoder.

 

As Suzie has said, some decoders do give the ability to reduce or 'zero' the values in CV3 and CV4, and this can be used for a rather crude simulation of braking (sometimes called 'shunt mode). 

 

ZIMO sound decoders have a properly designed progressive Brake Key feature which works in the way you describe. Set a reaslistically high CV4 to simulate a heavy train, use the Brake Key to slow or stop the loco. Quick 'dabs' to trim speed, longer applications to give greater Brake Force and hold 'on' continuously for full 'emergency' braking. Note, this is 'emergency' in the sense of real locos not toy trains. i.e. stops will be quick but not the same thing as 'hitting the red button' which can, of course, still be resorted to if necessary.

 

Decoders with this feature enabled are available from Digitrains.

 

Kind regards,

 

Paul

[tender]

Scott,

 

You may be new to DCC but you have hit the nail on the head by identifying this shortcomng of most DCC decoders.

 

ZTC controllers have a separate Brake Function. This works independently of the decoder.

 

As Suzie has said, some decoders do give the ability to reduce or 'zero' the values in CV3 and CV4, and this can be used for a rather crude simulation of braking (sometimes called 'shunt mode). 

 

ZIMO sound decoders have a properly designed progressive Brake Key feature which works in the way you describe. Set a reaslistically high CV4 to simulate a heavy train, use the Brake Key to slow or stop the loco. Quick 'dabs' to trim speed, longer applications to give greater Brake Force and hold 'on' continuously for full 'emergency' braking. Note, this is 'emergency' in the sense of real locos not toy trains. i.e. stops will be quick but not the same thing as 'hitting the red button' which can, of course, still be resorted to if necessary.

 

Decoders with this feature enabled are available from Digitrains.

 

Kind regards,

 

Paul

 

Hi Paul,

Some of my zimo sound decoders don't have this function enabled. Is it possible to enable it with a few CV adjustments or is it programmed in with the sound project?

[pauliebanger]

Hi Paul,

Some of my zimo sound decoders don't have this function enabled. Is it possible to enable it with a few CV adjustments or is it programmed in with the sound project?

 

Yes, but you will need the latest decoder software loaded to your decoder and the sound project adjusted to work with the Brake Key.

 

Kind regards,

 

Paul

[sjrixon]

That's interesting to read about zimo. I think I'll do more reading on that. I've played with a Lenz decoder with the shunt mode (didn't know that was what it was at the time) but as you say, quite crude.

[sjrixon]

Looking at Zimo.. The distance controlled stopping and shunting mode look interesting.. But I can't see anything about using a brake key, what am I missing?

 

http://www.zimo.at/web2010/documents/MX-KleineDecoder_E.pdf

[bigal10]

Hi Sott,

Welcome to the Wonderful World of Zimo, and realistic railway modelling!

 

If you wait around long enough, i'm sure Paul will be along with the definitive answers, but in the meantime, (as one of his, and Zimo fans) I suggest that you have a look at Digitrains' website and browse through their offerings for DigitrainsSound on Zimo, and for example, the Class 20 Diesel, in ActiveDrive and read through the notes, which explains about braking on F2

 

These are new functions on Zimo decoders, developed by Pauliebanger, in association with Zimo, and marketed by Digitrains, and one or two others, in the UK

 

- the usual disclaimers, I have no connection with any of the above, just a happy user!

 

Regards,

Alan.

[34theletterbetweenB&D]

I am very happy with the facility to reset CV3 and 4 when the light engine couples on, to reflect the train weight and braking capability. Then you operate, getting it right by making enough allowance for how far the train will run before it stops, and limiting speed, to what is appropriate for the brake capability. With CV4 in the 180 to 240 range for unbraked loose coupled goods (setting dependent on traction and load), you quickly discover why these trains rarely made much speed.

 

As the OP notes, the DCC simulation of the inertia of the train is a real asset, far better than manual control can achieve. From rest the speed step the train is to run at is set, and the decoder takes care of the smooooooth transition from rest to line speed. When the train reaches the braking point, speed step is set to zero, and the train glides predictably to rest in the desired location. I don't actively 'drive' in other words: I want to recreate the lineside experience of watching train movements. All the locos are set up in one of three groups with matching speed curve and maximum speed, and braking points for stop locations are indicated for all classes of operation.

 

There is an emergency stop available on Lenz - and many other similarly specified European made decoders - of F4, which gives direct control should  the need arise. More than enough to deal with any situation: if the operator drives properly in the first place. I'll use it half a dozen times a year, and bear in mind I operate daily; last time proved to be an interesting Pupa which had derailed a train.

[Nigelcliffe]

Looking at Zimo.. The distance controlled stopping and shunting mode look interesting.. But I can't see anything about using a brake key, what am I missing?

 

http://www.zimo.at/web2010/documents/MX-KleineDecoder_E.pdf

 

Lack of documentation :-), though in the case of an Austrian maker, the German language manuals are more up to date.

 

Documentation is a common problem across many DCC manufacturers, that details of new features often go un-documented for a considerable time. Sometimes its possible to work it all out, perhaps with the maker's sound software development tools to help. Other times you just wait until someone says they've got a new trick to work and chooses to actually document how it is done.

 

 

Then, it can get complicated with some people wanting commercial advantage for their projects and aiming to keep secret the details of how things are achieved.

 

 

 

A brake key is not unique to Zimo.  Soundtraxx have had it on their decoders for ages, and the cheap re-badged Soundtraxx decoders which carry a Bachmann label on them have this feature (Bachmann use a variety of decoder makers, so each model can be different).    But, a Soundtraxx decoder doesn't have the finesse of motor control offered by Zimo.

 

 

 

Most people have managed fine for ages without a brake key, so perhaps it is a matter of deciding on a sensible value for deceleration and then learning how to control the loco with your system ?

 

 

- Nigel

[sjrixon]

Nigel - There is a lot of sense in your last comment! My test loco is a Bachmann Prairie and I've actually got it running really nicley.  I think my 'DC' brain means I do need to learn to drive again, but when you get it right, it is amazing!

[Colin_McLeod]

As Paul says in his post ZTC dcc controller has a brake handle that works very realistically. Gentle application slows the train a bit and full application brings the train to a quick halt. Like stopping a real train there is a need to control the deceleration and getting to know the braking distances involved.

[pauliebanger]

I can only provide the tools.

 

If people choose not to use them, that's fine by me.

 

Those who have tried them, know. Those who haven't can carry on in blissful ignorance of what they are missing. Lol

 

And those with friends who sell ZIMO decoders which do not have such a feature enabled should declare their position so that posts can be interpreted correctly.

 

Kind regards,

 

Paul

[pauliebanger]

I am very happy with the facility to reset CV3 and 4 when the light engine couples on, to reflect the train weight and braking capability. Then you operate, getting it right by making enough allowance for how far the train will run before it stops, and limiting speed, to what is appropriate for the brake capability. With CV4 in the 180 to 240 range for unbraked loose coupled goods (setting dependent on traction and load), you quickly discover why these trains rarely made much speed.

 

As the OP notes, the DCC simulation of the inertia of the train is a real asset, far better than manual control can achieve. From rest the speed step the train is to run at is set, and the decoder takes care of the smooooooth transition from rest to line speed. When the train reaches the braking point, speed step is set to zero, and the train glides predictably to rest in the desired location. I don't actively 'drive' in other words: I want to recreate the lineside experience of watching train movements. All the locos are set up in one of three groups with matching speed curve and maximum speed, and braking points for stop locations are indicated for all classes of operation.

 

There is an emergency stop available on Lenz - and many other similarly specified European made decoders - of F4, which gives direct control should  the need arise. More than enough to deal with any situation: if the operator drives properly in the first place. I'll use it half a dozen times a year, and bear in mind I operate daily; last time proved to be an interesting Pupa which had derailed a train.

 

That's all interesting stuff. There is no braking effect on most decoders though, is there? Just various degrees of slowing down.

 

How many of these real locos had no separate braking function?

 

Kind regards,

 

Paul

[pauliebanger]

 

A brake key is not unique to Zimo. 

 

Most people have managed fine for ages without a brake key, so perhaps it is a matter of deciding on a sensible value for deceleration and then learning how to control the loco with your system ?

 

 

- Nigel

 

Nigel.

 

A brake key is not unique to ZIMO. One which works in a prototypical fashion is unique.

 

I managed fine for ages with my cycle which had no brakes, just a fixed rear gear that enabled me to slow down using the pedals. I learned how to control it with all it's deficiencies.

 

That did not stop me from greatly benefitting from the brakes my father fitted one Christmas.

 

That's the nature of technology - some embrace change, some actually innovate and influence change whilst others find excuses why the old fashioned way is the only way which matters.

 

Kind regards,

 

Paul

[34theletterbetweenB&D]

That's all interesting stuff. There is no braking effect on most decoders though, is there? Just various degrees of slowing down.

 

How many of these real locos had no separate braking function?

 This is very heavily dependent on what the operator wants in my view. I don't want to 'drive' directly as such. What I want is the simulation of the high inertia of trains in response to both power and braking, as seen when watching trains at lineside. As such I just let the DCC decoder do the business, and sit there grinning like a fool as the trains move off smoothly, and come to rest smoothly. Lovely.

[pauliebanger]

 This is very heavily dependent on what the operator wants in my view. I don't want to 'drive' directly as such. What I want is the simulation of the high inertia of trains in response to both power and braking, as seen when watching trains at lineside. As such I just let the DCC decoder do the business, and sit there grinning like a fool as the trains move off smoothly, and come to rest smoothly. Lovely.

 

Then a braking feature may well not be for you.

 

As I said, I am proving the option. A valid option is always to use the 'not for me, thank you', and I fully respect that view.

 

There is nothing different with my projects regarding the pleasure derived from CV3 and CV4, they are set with realistic values precisely for the effect you describe.

 

Adding a separate brake function allows very high CV4 values for that really 'heavy train' feel whilst allowing an extra degree of control to trim speed or to stop the loco.

 

You say you grin at the way your DCC decoder operates. That would not change, but with a brake, you would have the opportunity for fine control, for a more immersive experience, if you choose to use it.

 

Kind regards,

 

Paul

[Nigelcliffe]

Hi Paul,

Some of my zimo sound decoders don't have this function enabled. Is it possible to enable it with a few CV adjustments or is it programmed in with the sound project?

 

 

Effective from decoder software version V33.25 (read decoder software version in CV7 and CV65.)

 

CV309 = brake button, takes values 0 to 28 (or 0-29 in one place in the German manual), which, with usual Zimo conventions will be 0=no effect, 1=F1 to 28=F28, and (probably) 29=F0

CV349 = brake button deceleration rate, ie. deceleration to follow if key set in CV309 is active.

 

To make it work, set CV349 to be a much lower value than the deceleration set in CV4.

 

And, if wanted, attach braking noise sounds to the same function key.

 

The documentation shows the required firmware as available only on sound decoders.  It is not shown as available for the non-sound decoders.    

 

 

- Nigel

[Reorte]

Well this is all stuff that I never actually thought about with DCC but in hindsight all makes a lot of sense - I was happy with smooth acceleration and deceleration without even considering how much more variety is needed for really realistic operation (despite it obviously happening on the real railway). Mind you my layout isn't anywhere near complete enough to consider operating in a vaguely realistic fashion, but even so I've found this thread an interesting eye-opener. And here I went for DCC just to simplify the wiring!

[pauliebanger]

Effective from decoder software version V33.25 (read decoder software version in CV7 and CV65.)

 

CV309 = brake button, takes values 0 to 28 (or 0-29 in one place in the German manual), which, with usual Zimo conventions will be 0=no effect, 1=F1 to 28=F28, and (probably) 29=F0

CV349 = brake button deceleration rate, ie. deceleration to follow if key set in CV309 is active.

 

To make it work, set CV349 to be a much lower value than the deceleration set in CV4.

 

And, if wanted, attach braking noise sounds to the same function key.

 

The documentation shows the required firmware as available only on sound decoders.  It is not shown as available for the non-sound decoders.    

 

 

- Nigel

 

Nigel,

 

There we are.

 

No lack of documentation despite your previous assertion.

 

Everything in the Public Domain, no secrets.

 

There was a version available in the earlier firmware you mention, though it was never publically released by ZIMO.

 

In fact, the software versions jumped from V33.10 (issued 8 November 2013) which did not have the brake function, to V34 (issued 24 June 2015) but the most complete form is available only in the latest software, (V35.2) as I posted earlier.

 

Kind regards,

 

Paul

Edited December 22, 2015 by pauliebanger

[tender]

Effective from decoder software version V33.25 (read decoder software version in CV7 and CV65.)

CV309 = brake button, takes values 0 to 28 (or 0-29 in one place in the German manual), which, with usual Zimo conventions will be 0=no effect, 1=F1 to 28=F28, and (probably) 29=F0

CV349 = brake button deceleration rate, ie. deceleration to follow if key set in CV309 is active.

 

To make it work, set CV349 to be a much lower value than the deceleration set in CV4.

 

And, if wanted, attach braking noise sounds to the same function key.

 

The documentation shows the required firmware as available only on sound decoders.  It is not shown as available for the non-sound decoders.    

 

 

- Nigel

Many thanks for that Nigel.

Is the version number a straight Cv read (CV7=33, CV65=25) or is there some convoluted manipulation required to arrive at the version number?

[sjrixon]

Why only the sound versions? I really have no interest in sound.

[bigal10]

Crikey, Scott,

 

How can you live without sound?

 

Ok, then, if not sound, what about lights, I know Prarie's were not big on lights, no kettles ever were, which is probably why I stuck mainly to big, smelly oil burners, - but think about flickering fire boxes, and real smoke...

 

Oh yes, DCC can do all of that, and more! - most of my diesels now have cab lights that auto fade to nil, when the loco moves off..

Can't do that in DC I'll bet?

 

Regards,

 

Alan

[sjrixon]

I understand why people would like and use sound.. But I don't think it's for everyone.